The invention relates to an automotive seat belt buckle pretensioner, and particularly to a mounting mechanism for a seat belt buckle pretensioner. The invention is especially applicable to seat belt pretensioners that employ pyrotechnic cartridges as the power source.
Seat belt buckle pretensioners employing explosive pyrotechnic gas generators as the power source are shown in U.S. Pat. Nos. 5,403,037 and 5,639,120. Typically, a seat belt buckle pretensioner comprises a pyrotechnic cartridge mounted in a housing that is suitably affixed to a concealed portion of the automotive seat structure. A cylinder extends from the housing for slidably supporting a small piston that is operatively connected to the seat belt buckle by a flexible cable that is trained around a pulley aligned with the aforementioned cylinder.
Should the automotive vehicle experience an abrupt deceleration, a sensor causes an electrical signal to be delivered to the pyrotechnic cartridge, which explosively generates a relatively high gas pressure against the piston. The piston slides rapidly along the cylinder to exert a pulling force on the cable; the cable travels downwardly around the pulley to draw the seat belt buckle angularly downwardly, so as to tension the associated seat belt.
In many cases there may be only a relatively small space within the automotive seat structure for operatively mounting the seat belt buckle pretensioner assembly. The present invention relates to a mounting mechanism for a seat belt buckle pretensioner assembly that is separate from the pretensioner componentry, whereby the mounting mechanism can be designed to fit different installation space requirements without requiring any redesign of the pretensioner components.
In preferred practice of the invention the mounting mechanism comprises a single bracket, stamped or otherwise formed, so that one wall of the bracket is attachable to the available mounting surface on the seat structure, while another wall structure is rigidly affixed to the mounting bracket to act as a mounting device for the operating componentry of the seat belt buckle pretensioner. The single mounting bracket can be reconfigured to meet different installation space requirements. The mounting bracket and associated wall structure are designed to form a protective enclosure for the pulley.
Further features of the invention will be apparent from the attached drawings and description of an illustrative embodiment of the invention.